Method, an image processing device for dividing an array of pixels into slices and tiles, and a system for encoding the slices and tiles into a video stream

1. A method for dividing an array of pixels into slices and tiles for encoding the array of pixels into an encoded video stream by means of a first encoder arranged in a first image processing circuitry and a second encoder arranged in a second image processing circuitry, wherein pixels of the array of pixels are arranged at regular intervals along a vertical direction and a horizontal direction, wherein each slice is separated by a straight horizontal line over the full width from the respective adjacent slices and is encoded without the need for access to image data relating to other slices and each tile is separated by a vertical straight line over the full height of a slice from respective adjacent tiles in the same slice and is encoded without the need for access to image data relating to other tiles, wherein the array of pixels consists of a first subset of pixels having pixel data stored in a first buffer arranged in the first image processing circuitry and a second subset of pixels having pixel data stored in a second buffer arranged in the second image processing circuitry, wherein a first border between the first subset of pixels and the second subset of pixels is tilted at a tilt angle in relation to the array of pixels, the method comprising: dividing the array of pixels into two or more slices; and dividing each slice into two or more tiles, wherein the two or more tiles of each slice consists of a first subset of tiles and a second subset of tiles, wherein the first subset of tiles and the second subset of tiles are disjunct and the first subset of tiles is to be encoded by the first encoder and the second subset of tiles is to be encoded by the second encoder, wherein the act of dividing each slice into two or more tiles comprises setting a second border between the first subset of tiles and the second subset of tiles at an offset along the horizontal direction between two adjacent slices of the two or more slices such that the second border between the first subset of tiles and the second subset of tiles in two adjacent slices are not aligned along the horizontal direction, wherein the offset is based on the tilt angle such that the number of pixels to be encoded into the first subset of tiles of each slice that have pixel data stored in the second buffer plus the number of pixels to be encoded into the second subset of tiles of each slice that have pixel data stored in the first buffer is reduced in relation to not using an offset, and wherein the method further comprises: transferring, from the second buffer to the first encoder, pixel data of pixels to be encoded into the first subset of tiles of each slice having pixel data stored in the second buffer; encoding the first subset of tiles by means of the first encoder; transferring, from the first buffer to the second encoder, pixel data of pixels to be encoded into the second subset of tiles of each slice having pixel data stored in the first buffer; and encoding the second subset of tiles by means of the second encoder.

2. The method of claim 1, wherein the tilt angle is constant along the first border between the first subset of pixels and the second subset of pixels.

3. The method of claim 1, wherein the tilt angle varies along the first border between the first subset of pixels and the second subset of pixels, wherein the act of dividing the array of pixels into two or more slices comprises dividing the array of pixels into three or more slices, wherein the act of dividing each slice into two or more tiles comprises, for each two adjacent slices of the three or more slices, setting the second border between the first subset of tiles and the second subset of tiles of each slice of the two adjacent slices at an offset, wherein the offset is based on a local tilt angle of the first border between the first subset of pixels and the second subset of pixels in the two adjacent slices.

4. The method of claim 3, wherein the first border between the first subset of pixels and the second subset of pixels is curved.

5. The method of claim 3, wherein the first border between the first subset of pixels and the second subset of pixels is tilted at a constant but separate tilt angle in separate horizontal portions of the array of pixels.

6. The method of claim 5, wherein the act of dividing the array of pixels into three or more slices comprises dividing the array of pixels into four or more slices by dividing each separate horizontal portion of the array of pixels into two or more slices such that, for each two adjacent horizontal portions, a third border between the two adjacent horizontal portions is aligned with a fourth border between two slices.

7. The method of claim 3, wherein the local tilt angle of the first border between the first subset of pixels and the second subset of pixels in the two adjacent slices is determined as an average tilt angle in the two adjacent slices.

8. The method according to claim 1, wherein sizes of corresponding tiles of the two or more tiles of each of the two or more slices are the same in each of the two or more slices.

9. A non-transitory computer-readable storage medium having stored thereon instructions for implementing the method according to claim 1 when executed by a device having processing capabilities.

10. An image processing device for dividing an array of pixels into slices and tiles for encoding the array of pixels into an encoded video stream by means of a first encoder arranged in a first image processing circuitry and a second encoder arranged in a second image processing circuitry, wherein pixels of the array of pixels are arranged at regular intervals along a vertical direction and a horizontal direction, wherein each slice is separated by a straight horizontal line over the full width from the respective adjacent slices and is encoded without the need for access to image data relating to other slices and each tile is separated by a vertical straight line over the full height of a slice from respective adjacent tiles in the same slice and is encoded without the need for access to image data relating to other tiles, wherein the array of pixels consists of a first subset of pixels having pixel data stored in a first buffer arranged in the first image processing circuitry and a second subset of pixels having pixel data stored in a second buffer arranged in the second image processing circuitry, wherein a first border between the first subset of pixels and the second subset of pixels is tilted at a tilt angle in relation to the array of pixels, the image processing device comprising circuitry configured to execute: a first dividing function configured to divide the array of pixels into two or more slices; and a second dividing function configured to divide each slice into two or more tiles, wherein the two or more tiles of each slice consists of a first subset of tiles and a second subset of tiles, wherein the first subset of tiles and the second subset of tiles are disjunct and the first subset of tiles is to be encoded by the first encoder and the second subset of tiles is to be encoded by the second encoder, wherein the second dividing function is further configured to set a second border between the first subset of tiles and the second subset of tiles at an offset along the horizontal direction between two adjacent slices of the two or more slices such that the second border between the first subset of tiles and the second subset of tiles in two adjacent slices are not aligned along the horizontal direction, wherein the offset is based on the tilt angle such that the number of pixels to be encoded into the first subset of tiles of each slice that have pixel data stored in the second buffer plus the number of pixels to be encoded into the second subset of tiles of each slice that have pixel data stored in the first buffer is reduced in relation to not using an offset, wherein the circuitry is further configured to execute: a first transferring function configured to transfer, from the second buffer to the first encoder, pixel data of pixels to be encoded into the first subset of tiles of each slice having pixel data stored in the second buffer; a first instructing function configured to instruct the first encoder to encode the first subset of tiles, wherein the first encoder is configured to encode the first subset of tiles; a second transferring function configured to transfer, from the first buffer to the second encoder, pixel data of pixels to be encoded into the second subset of tiles of each slice having pixel data stored in the first buffer; and a second instructing function configured to instruct the second encoder to encode the second subset of tiles, wherein the second encoder is configured to encode the second subset of tiles.

11. The image processing device of claim 10, wherein the tilt angle varies along the first border between the first subset of pixels and the second subset of pixels, wherein the first dividing function is configured to divide the array of pixels into three or more slices, and wherein second dividing function is configured to, for each two adjacent slices of the three or more slices, set the second border between the first subset of tiles and the second subset of tiles of each slice of the two adjacent slices at an offset, wherein the offset is based on a local tilt angle of the first border between the first subset of pixels and the second subset of pixels in the two adjacent slices.

12. The image processing device of claim 11, wherein the first border between the first subset of pixels and the second subset of pixels is tilted at a constant but separate tilt angle in separate horizontal portions of the array of pixels, wherein the second dividing function is configured to divide each separate horizontal portion of the array of pixels into two or more slices such that, for each two adjacent horizontal portions, a third border between the two adjacent horizontal portions is aligned with a fourth border between two adjacent slices.

13. The image processing device of claim 11, wherein the second dividing function is further configured to determine the local tilt angle of the first border between the first subset of pixels and the second subset of pixels in the two adjacent slices is as an average tilt angle in the two adjacent slices.